The present invention relates to shut-off devices for shutting-off the flow of a material from a passage in a body. The invention is particularly useful as an artificial sphincter for shutting-off a channel in a patient's body communicating with an opening through the skin of the patient's body. The invention is therefore described below with respect to such application, but it will be appreciated that the invention could advantageously be used in other applications as well.
Various types of ostomy/ileostomy procedures are used to correct difficulties in the intestinal track, such as an obstruction or cancer. In such a surgical procedure, the intestine is usually severed, and an end of the intestine is brought through an incision in the abdominal wall and is secured adjacent the patient's skin, forming an opening, or "stoma", to permit passage of stool material. Such a procedure results in loss of fecial continence for the patient, and therefore the patient is usually required to wear a stool pouch on the outside of the body in order to collect the stool passing through the stoma. Various types of artificial sphincters have been devised, including mechanical and magnetic types, in order to eliminate the need for wearing external stool pouches. However, the known artificial sphincters have not proved satisfactory, and therefore in most cases the patient must still wear stool pouches despite the aesthetic, social and emotional problems involved.